Recent Posts
Featured Posts

Why is ice so blue?

Last week I promised you a walk up onto the moorland fringe in search of one of our most spectacular and enigmatic upland birds, however, despite living in a very rural area and the chances of encountering anyone on my walk are virtually nil, in order to comply closely with the government guidelines, I am restricting my daily walks to the woods and loch close to home.

To enjoy and appreciate the freedom and wellbeing that our beautiful countryside offers, in a variety of meaningful activities, is our right and inheritance. To be denied access to the greater outdoors, albeit temporary, is something that frustrates all of us although we completely understand this must be done. These are, without question, difficult times as we learn to take pleasure from the limited freedom our gardens afford; watching the birds start their pre-nuptial activities, frogs spawning in the garden pond and many other signs of an incipient spring as it begins to emerge from its winter slumber. We are the lucky ones, let’s spare a thought for those who do not have access to a garden and the pleasure it can provide, the discipline shown by so many self-isolating from loved ones and offer hope that the pandemic will end, and end it will when life returns to better days!

Living in a post-glacial valley, there are constant reminders all-around of a landscape shaped and sculptured by ice, following the retreat of the last glacier some 15,000 years ago. This thought led me to a question that I am frequently asked when visiting glaciers in the far north and I thought I would share this with you. Why is some ice so blue?

The reason why some ice can be such an intense blue colour is the result of snow falling on a glacier and then being subsequently compressed through time. Imagine hundreds or even tens of thousands of years of snow accumulating on a glacier and the incredible amount of pressure that causes. Glaciers flow like a river and in this case a piece of ice has carved off the face of the glacier. When the ice is compressed, the air bubbles are squeezed out and in turn the ice crystals get bigger. Now here is where it gets a little technical. The red (long wavelengths) part of white light is absorbed by the ice and the blue (short wavelengths) light is transmitted and scattered. So, the longer the path of light has to travel through ice, the more intense blue it appears. Wow, not a lot of people know that!

Follow Us